bobcat 732 engine problem

[chrisdvorak]

I have a bobcat 732 skid steer that wont start. the engine is a ford 4cyl 1.6l gas. I did a compression check on it when I first got it and found that no 1 and 2 cylinders were very low 3 and 4 were normal after pulling head found 2 burnt exhaust valves. I replaced and lapped all valves and installed a new head gasket after getting it all back together and adjusting the valves I got it to start and run ok for about 5 mins at which point I noticed that the engine was getting very hot. I shut it down and removed the thermostat thinking that may be the problem, but after I let it cool down it would start then die after a few more tries it wont start at all. I have checked fuel, had the carb apart 3 times and have seen nothing out of the ordinary, it has good spark and air filter is not blocked. everything seems to be in time, I had the front cover off and looked at the timing chain which is tight and the hash marks line up. I am running out of ideas any input would be appreciated. FYI its the same engine as a 1980 ford fiesta.

-thanks

 

[DJ54]

Assuming it did not overheat before doing the valve job, is there any chance the new head gasket was installed backwards/upside down, closing off some ports??

Not familiar with that engine, but is there a fuel shut off solenoid on the carb.?? Could be sticking. Checked for wet plugs after trying to start..?? Is it a manual choke, or automatic..?? Manual, or electric fuel pump..??

 

[chrisdvorak]

when I got the machine it was not running so Im not sure if it was running warm before or not the head gasket is in correctly as the studs only line up one way. there is no solenoid on the carb, all manual the fuel pump is electric and supplies plenty of fuel. the plugs are wet. Im thinking the distributor timing may be off? anyone know if this needs to be set at TDC or 12 degrees?

-thanks

 

[flyerdan]

If it's the same Ford engine that they used in the 722 then it's 12 BTC I've got the Ford parts of the manual and tech specs in .pdf if you'd like them.

 

[chrisdvorak]

I have adjusted the points again at 12 BTC with still no luck seems like I'm missing something but don't know what to try next?

 

[RPW]

All I can say maybe the valves are adjusted to tight. Check compression again. On mine (which I need a new carburetor) it also runs hot but I believe mine is because the radiator has many bent fins. Also pull the carburetor bowl and check for water.

Good luck.

 

[chrisdvorak]

Thanks RPW I will check compression again. I am just thinking out loud here but when I had the head off to put in the new valves I had to remove the intake manifold, the gasket got slightly damaged in the removal but instead of replacing it I just reinstalled the old one without thinking too much about it. could this damaged gasket be causing a fuel starvation issue because it was sucking air? maybe that would explain the engine getting too hot when it was running due to a lean mixture? Also, am I right in assuming the valves are to be adjusted at TDC and the distributor timing and points are done at 12BTC

 

[chrisdvorak]

anyone know the symptoms of a bad intake manifold gasket?

 

[flyerdan]

Usually they will start and idle with an intake leak, but since it's running so lean will die out when you open the throttle. The test for a leak is to play an unlit propane torch or o/a torch over the top of the manifold, if there is a leak it will suck in the gas and increase rpm.

 

[chrisdvorak]

well I went ahead and replaced the intake manifold gasket yesterday but was not able to try to start it up as the starter failed. now have to wait another week for a starter. when it rains it pours

 

[chrisdvorak]

okay I got the machine cranking again. but still no start. did another compression test and found this
no 1- 30psi
no 2 -90psi
no 3-120psi
no 4-120psi
I would think if worn piston rings were the problem the numbers would be lower across the board? also with 2 good cylinders shouldn't it at least try to start? plugs are wet and I have blue spark. when it was running briefly it was not smoking like it would if the rings were worn.
also I adjusted the valves by the rule of 9, is there any different way I should adjust them?

-thanks

 

[chrisdvorak]

anyone?

 

[chrisdvorak]

Okay so I've found out some new details, after putting raw fuel into the spark plug holes I got it to start and run for a few seconds so this confirms a carb problem, so I rebuilt the carb. And thoroughly cleaned it (wasn't very dirty to begin with) and still no change. Engine now has plenty of vacuum. Previous owner updated the fuel pump to a small electric one, is it possible that this is creating too much pressure for the carb?

 

[DJ54]

I did a quick Google search for an '80 fiesta 1.6L fuel pump pressure, and came up with this as a match for a universal fuel pump for one.

80 1980 Ford Fiesta Electric Fuel Pump 1.6L 4 Cyl Beck Arnley
Sale Price:
$59.23
Quantity:

(34) In Stock
Product SKU: 152-0576
Product Note: Electric Fuel Pump -- UNIVERSAL TYPE; Universal Type 2-1/2 To 4-1/2 Psi Rating


If the PO used a pump like a Mr. Gasket, they may have gotten the higher pressure one 4-7 psi. They do make a lower pressure one 2-3.5 psi.

I guess you could make sure the carb. bowl is full, then relieve the pressure off the line, and see if it would start.

 

[chrisdvorak]

Thanks DJ54, I tried filling the carb bowl and starting it with no fuel pressure and it still would not start. I looked Into my fuel pump and it states only 1.5 - 4 psi so I guess it's not a fuel pressure problem. I am out of ideas for the carb except for just replacing it with a new one but I really don't want to spend 300$+ only to have the same problem in the end.
By the way it's a zenith model 68 updraft.
If anyone else has any other ideas please chime in!

 

[DJ54]

Spark, fuel (wet plugs) and air, it ought to at least pop. Almost sounds like more of a timing issue.

I'm not sure what 4 cyl. engine was used in Ford Rangers in the early 80's, but the one they gave me for a work truck over a period of a year's time got pretty week on hills, like there was no spark advance. Finally got one of our mechanics ( a real one) that found the rivet that holds the advance plate had sheared off. He put a new one in, and it ran like a striped ape after that.

 

[chrisdvorak]

I have chased a timing problem already to no avail. I advanced and retarded the timing with no change right now I just need to get the engine running and it should run without the vacuum advance hooked up. Once it's running I can fine tune it.

 

[DJ54]

Is it possible it's getting too much fuel, like over choking and engine, and a flooded condition..?? Plugs gapped properly..??

Your one quote "Set the points @ 12º BTDC" kinda' threw me. I'll assume just a misquote, and points were set to proper gap, and timing set to 12º BTDC. Not sure what the gap would be on that engine, but the older fords IIRC were right at .019". A buddy of mine years ago used a business card as a feeler's gauge, LOL...

 

[chrisdvorak]

Yes it was a misquote. Points are set to .025 as per manual. Ignition timing set at 12BTDC. Today I removed the spark plugs and with each cyl at TDC I used compressed air to clean and dry each piston, did the same to the plugs to ensure everything was bone dry and reinstalled them. Then I set full choke and cranked the engine for a good 20 seconds ( carb bowl had fuel in it) and the plugs were still bone DRY. Has to be a blockage in the carb somewhere I would think but I have cleaned and inspected every part of it countless times and everything is clean as a whistle??

 

[DJ54]

Set to full choke, but did you check to see if the choke plate is fully closed..??